Evanescent waves cannot exist in the near-field! Thomas Prevenslik QED Radiations Discovery Bay, Hong Kong Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8,

Introduction Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 The Planck ‘s BB theory relating EM radiation to temperature defines the SB radiative heat transfer between hot T H and cold T C surfaces EM = Electromagnetic SB = Stefan-Boltzmann Recently, solutions of Maxwell’s equations show radiative heat transfer for nanoscale gaps is enhanced by 3-4 orders of magnitude above Planck theory 2 Valid if the surfaces are separated by macroscale gaps.

Problem Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 The Maxwell solutions ignore the fact QM denies atoms under the EM confinement in nanoscale gaps to have the heat capacity to fluctuate in temperature as required by the FDT. QM = quantum mechanics FDT = fluctuation-dissipation theorem. 3

Planck v. Near-Field Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Planck never stated his theory bounded the near-field, but was surely aware heat flow from close surfaces restricts heat transfer to the conduction limit. But if so obvious, How then did the notion originate of increasing heat transfer by nanoscale gaps ? 4

Origin Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Near-field heat transfer began almost 50 years ago on the counter-intuitive conjecture by academia that BB heat transfer is greatest at zero surface spacing. Based on practical grounds it is impossible to bring BB surfaces to zero spacing without making thermal contact, so any near-field enhancement cannot be achieved. But academia is not always practical Even if the BB surfaces are close but not contacting, the classical assumption was made that distinct temperature differences exist between hot an cold surfaces. QM negates close surfaces to have same temperatures 5

Purpose Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 To question the conjecture that near-field heat transfer is enhanced above Planck theory because By QM, the Maxwell solutions cannot satisfy the FDT that requires temperatures to fluctuate in nanoscale gaps and Propose SB is still valid in near-field 6

Overview Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 D = vacuum d + dead space 2d s. By QM, dead space lacks heat capacity  No temperature fluctuations FDT not satisfied Radiation passes through D without absorption allowing the SB to be valid for all gaps d < D, d < D d s d d s 7 D D = Smallest gap where SB is valid, but for d < D

Heat Capacity of the Atom 8 Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Classical Physics (MD, Comsol) QM (kT = 0) kT eV Classical Physics (MD, Comsol) Nanoscale Macroscale 1950  Teller & Metropolis MD  PBC  valid for > 100  m Today, MD used in discrete nanostructures ! 1900  Planck derived the QM law In nano structures, the atom has no heat capacity by QM 1912  Debye’s phonons  h  = kT  valid for > 100  m Today, phonons used in nanostructures !

QM in the Near Field 8 QM Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 At 300K, = 100 microns  D = 50 microns Reduce gap d < 50 microns What is Q SB for d < 50 microns? Same as for d = 50 microns. SB is valid for all d < 50 microns d < 50  m 50  m

Maxwell Solutions Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Solution of Maxwell’s equations in the near field assume 9 where  ( , T) = frequency form of the Planck law evaluated for evanescent waves in the NIR where the atom has heat capacity Maxwell solutions exclude Maxwell solutions exclude  ( , T) under EM confinement of the penetration depth of the evanescent wave at UV frequencies where the heat capacity vanishes

Maxwell Solutions Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Maxwell Solutions Evanescent Waves - T H = 800 K, T C = 200 K 10  = 3x10 14 rad/s f = 4.8x10 13 /s NIR = 6.3 microns T = 800 K  ( ,T) = eV d = 100 nm UV = 200 nm  = 15x10 15 rad/s  ( ,T) = 5x eV Planck law  ( ,T) !!!

SB and Maxwell In near-field, QM invalidates FDT Maxwell solutions of evanescent tunneling are questionable Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, Validity of SB in Near-Field? QED Tunneling

Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, QED induces excluded radiation to create photons that tunnel across the gap and allow the SB to remain valid SB Number of QED Photons QED QED Photon Valid SB in Near-Field requires:

Summary Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, QSB is constant for all d 2. Heat transfer H by Maxwell exceeds SB by 3-4 orders 3. Q QED = Q SB for all d, but E and NP of QED photons vary 4. QED does not increase heat transfer above SB

Conclusions Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 QED is simple compared to computationally intensive Maxwell solutions QED conserves excluded SB radiation by creating standing wave photons that tunnel SB radiation across the gap. QED supersedes tunneling by evanescent waves Planck’s limit on far field radiative heat transfer is not exceeded in the near field. QM negates the classical physics assumption in Maxwell solutions that atoms in nanoscale gaps satisfy the FDT 14

QM in Nanotechnology Nanoparticle Combustion EM Confinement QED Heat Transfer Nano coatings Disinfection Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8,

NP Combustion Carbon NPs did not combust at 600 C? C + O 2  CO 2 Repeat for micron size porous carbon, Carbon NPs not found in SEM  Complete NP combustion ? Tensile tests show NPs enhance properties  Carbon enhances aluminum bond ? DFT disproved QM Interpretation: NPs do not have heat capacity Macro carbon increases in temperature. NPs remaining after combustion stay at high temperature and also combust. Temperature changes do not occur in NPs Add carbon NPs to a molten aluminum in air ( 0xygen ), cool to ambient and take SEM micrographs Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8,

QED Heat Transfer By classical physics, heat transfer proceeds by 3 modes: Conduction Radiation Convection Proposal QED is the Fourth Mode of Heat Transfer, but only at the nanosclae Simplified form of QED in Interaction of light and matter from that advanced by Feynman EM energy into QM box with refractive index n sides separated by d  Create QED radiation at /2 = d f = (c / n) / = 2d E = h f Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8,

Nano gaps have high surface-to -volume ratio. Absorption places surface atoms under high EM confinement, but QM precludes temperature increase. QED conserves the trapped energy to EM radiation... QED: Simplified Definition for n = 1 f = c / = 2d E = h f EM Confinement Heat THTH TCTC Nano Gaps QED d = /2 No Temperature increase Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 QED Radiation 18

Nanocoatings Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Nano Coatings conserve heat without temperature increase as QED radiation bypasses natural convection to enhance heat transfer Heat Macro Coating > 1 micron Temperature increase Natural convection QED Radiation Nano Coating < 100 nm Substrate 19 No temperature increase

Disinfection Hand-held bowls are provided with nanoscale ZnO coatings to produce UVC from body heat and disinfect Ebola and drinking water No electricity – West Africa UVC is created with 50 nm coating of ZnO, = 2 nd. For n = 2.5,  254 nm LEDs in the UVC are thought to provide the future disinfection of drinking water. But LEDs require electricity and cannot achieve the 100% efficiency of QED disinfection. Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8,

Protocols Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8, 2016 Drinking water Disinfection 38,000  W-s/cm 2 Hold water in bowl for at least 7 s 21 Ebola Disinfection 400  W-s/cm 2 Move bowl over surface in < 1 s scans Q  6,000  W/cm 2

Questions & Papers Bremen Workshop on Light Scattering 2016, Bremen, March 7 - 8,